utils.py

import torch
import numpy as np
import torch
from PIL import Image, ImageOps
from torchvision.transforms import ToPILImage, ToTensor
totensor = ToTensor()
topil = ToPILImage()



def resize_and_crop(img, size, crop_type="center"):
    '''Resize and crop the image to the given size.'''
    if crop_type == "top":
        center = (0, 0)
    elif crop_type == "center":
        center = (0.5, 0.5)
    else:
        raise ValueError

    resize = list(size)
    if size[0] is None:
        resize[0] = img.size[0]
    if size[1] is None:
        resize[1] = img.size[1]
    return ImageOps.fit(img, resize, centering=center)


def recover_image(image, init_image, mask, background=False):
    image = totensor(image)
    mask = totensor(mask)[0]
    init_image = totensor(init_image)
    
    if background:
        result = mask * init_image + (1 - mask) * image
    else:
        result = mask * image + (1 - mask) * init_image
    return topil(result)


def preprocess(image):
    w, h = image.size
    w, h = map(lambda x: x - x % 32, (w, h))  # resize to integer multiple of 32
    image = image.resize((w, h), resample=Image.LANCZOS)
    image = np.array(image).astype(np.float32) / 255.0
    image = image[None].transpose(0, 3, 1, 2)
    image = torch.from_numpy(image)
    return 2.0 * image - 1.0


def prepare_mask_and_masked_image(image, mask):
    
    image = np.array(image.convert("RGB"))
    image = image[None].transpose(0, 3, 1, 2)
    image = torch.from_numpy(image).to(dtype=torch.float32) / 127.5 - 1.0

    mask = np.array(mask.convert("L"))
    mask = mask.astype(np.float32) / 255.0
    mask = mask[None, None]
    mask[mask < 0.5] = 0
    mask[mask >= 0.5] = 1
    mask = torch.from_numpy(mask)

    masked_image = image * (mask < 0.5)

    return mask, masked_image